S. Piacentini

A bullet that doesn't just pierce one target but leaves marks in several layers of armor. That's roughly how superheavy dark matter behaves, and it's what the DarkSide-50 detector was built to catch for the first time. The usual suspects for dark matter (weakly interacting massive particles, or WIMPs) pass through matter almost unnoticed, occasionally bumping into a nucleus.

Deep in a cave beneath the Italian Apennines, a tank of gas sits in the dark. Inside, charged particles fly through, leaving faint flashes of light in their wake. These flashes are like the wake of a boat on dark water: they reveal where the particle went and how fast.